Portable concrete rodding machine



March 20,1945. M ZE. WHVITEMAN 2,372,163

PORTABLE CONCRETE RODDING MACHINEA Filed oct. 51, 19414 2 sheets-sheet 1 25 I i v Z ff /fvVE/VTOR Arma/vars.

March 20, 1945. M. E. wHlTEMAN PORTABLE CONCRETE RODDING MACHINE Filed Oct. 251|., 1941 2 Sheets-Sheet 2 "i" luv lllllllllllll /A/rE/vroR ArraRA/Eys.

' Mer/N E. WH/TEMAN i tL- J invention relates to a portable concrete redding or `screeding machine.

` rimary object of theinvention is `to-provide aiiportable concrete redding or screeding machine lthat may be advantageously utilized in the'` construction of concrete floors, concrete y slabslfandthe like. Heretefore it has been customary practice in the construction of a concretek oonto temporarily ,mount at the side boundaries ofthe concrete thatvis to be poured guideflstrips or grounds, the `rtop surfaces of which arel arranged at the desired levelto which the: concrete is to be poured. Then a rod or screed `isvworlied back and forth transversely with respect to` the grounds to strike eff the excessllconcrete and `to render the concrete level with,` the top surface of the grounds. The reciprocationfofthe"rod also tends to work the cernentand .fine aggregate toward the surface, after `which the concrete may be surfaced manually or bymachine, or if desired, a nish coat of. cement may .be applied thereover.

The present invention contemplates a `machine foraccomplishing the above-mentioned purpose wherein the machine is adequately heavy tewerk and strike off an adequate area of poured coneretebutwill also beadjustably and yieldablysupported so'thatY the entire weight of the mac "ne gdoesvnot'rest on the grounds or .guide stri this manner the` machine `operates wit aminimurn-ameunt of friction and danger of. disturbing the grounds is largelyeliminated.

f Another object of the inventienis to provide ajportable concrete redding er screeding machine whichfis of relatively simple and durable censtruction` and which is readily portable from job'to job.

Another .object of the invention is to'provide a portable concrete redding or screeding machine employingv transversely movable screeds` so arranged that movements of the screeds are transverse andv opposite so that Vibratory tendencies created`-lby the movements of the screeds are largelyl--neutralized i whereby the machine is causedrto-operate smoothly and efficiently.

,With the foregoing and other objects in View, which'rwillbe made manifest inthe following detailed description and specifically pointed out in theappended claims, reference is had to the accompanying .drawings for an illustrative embodiment of the invention, wherein:

-Figureir is a top plan view of a concrete floor illustrating grounds or guide strips as having l:e in ,setgandy illustrating the redding or screedi indicated;

UNITED y STATES PATENT OFFICE ff 2,372,163: v n Y 'rioRrAnLooNoRE'rE RonDING E iuaivin E. Whiteman, nos Angeles, Calif.

xptlitatib october 31, 1941)'. seriaiNq. 417,235A n iiolaims. (01.94445) l y L y ing machine embodying the presentV invention in operative position thereon;

Fig. 2 is a front view in elevation of the portable concrete redding or screeding machine;

. Fig. 3 is a vertical section taken substantially upon the line 3 3 upon Fig. 1 in the direction indicated;

Fig. 4 isa vertical section taken substantially upon the line 4-4 upon Fig. 1 in the direction Fig. 5 is a vertical section taken substantially upon the line 5--5 upon Fig. 1V in the direction indicated;` and i y i Fig. 6 is a horizontal section taken substantially upon the line 6--6 upon Fig. 4 in the direction indicated.` l

Referring to the accompanying drawings whereinsimilar reference characters designate similar `parts throughout, IIl and II indicate grounds or guide strips that are usually mounted temporarilyat the sides of an area offloor space that is to be vpoured with concrete C. The irnpreved portable concrete redding machine comprises a transversely extending plate or frame I2 on which is preferably mounted a gear box I3 driven by any suitable source of power, such as an electric motor I4. A belt or chain I5 may connect the motor I 4 with thegearbox.

vThe gear box` has on its underside an eccentric I6 the eccentric pin of which is connected by a connecting rod I1 to a pivot I8. A handle I9 extends upwardly and forwardly from the gear box and may be equipped with an electric switch 2Il-n controlling the electric current delivered through conductors 2l to the electric motor I4.

On the under side ofthe Aframe I2 adjacent opposite ends thereof there are cross' bars 22 and v 23, these being pivotallyfrnounted adjacent their centers onpivot studs 24. The rear ends of the cross bars 22 and 23 are pivotally connected as at 25 and 26 to transversely extending angle irons 21. A screed or rod 28 preferably formed of woodis detachably mounted upon the angle irons 21, such as by belts 29. In a similar manner, the forward ends of the cross bars 22 and 23 are pivotally connected by means of the pivot pin I8 and a pivot 30 to angle irons 3| on which a forward screed 32 is detachably mounted as by bolts 33.

The screeds 28 and 32 are slightly greater in lengtlrthan the distance between the grounds and the guide strips I0 and II, and are thus mounted for transverse back and forth movedotted lines on Fig.` 1.

Adjacent each end of the frame there is hingedly mounted as by hinges 34 supporting arms 35 which provide trunnions or axles for supporting wheels or discs 36. The arms 35 are yieldably urged downwardly against the top of the frame by means of coil compression springs 31 disposed about bolts 38 having adjustable nuts 39. 'I'he discs or supporting wheels 36, together with their associated structure, serve to yieldably support the major portion of the weight of the machine so that, although the bottom surfaces of the screeds or rods 28 and 32 rest and rub on the top surfaces of the grounds I and Il, the entire weight of the machine is not caused to rest on the groundsbut is largely carried by the supporting wheels or discs 36.

The operation and advantages of the improved portable roddng or screeding machine are as follows: When the concrete is poured between the forms l0 and Il, the ma-chine is started up by closing switch 20. This causes thel motor I4 to drive the eccentric I6 through the gear box I3 with the result that the connecting rod causes the forward screed. 32 to move back and forth in a transverse direction. The cross bars 22 act as simple levers causing the rear screed 28 to move back and forth transversely in a similar manner. The movements of the two screeds are however simultaneous and opposed. That is, while the forward screed is moving toward the right the rear screed is forced to move towardthe left and when the forward screed is moving toward the left, the rear screed is forced to move toward the right. The machine is slowly pulled forwardly in a longitudinal direction by the handle I9 while the reciprocatory movement of the screedsl is taking place.

The forwardscreed serves largely to strike off or to level out the excess concrete as indicated in Fig. 3 and the rear screed performs largely a nish screeding or redding operation filling the narrovv'grooves that maybe left by the thin supporting wheels or discs 3B. The extent to which the supporting wheels or discs 36 support theweight of the machine may be varied or adjusted by means of nuts 39 and adjustment of these nuts may be required whenever the depth to which the concrete is poured is varied.

While it is possible to construct a machine having merely one screed, the use of two screeds is highly preferable in that the opposed motionsof the screeds tend to neutralize each other insofar as vibration of the machineis concerned. Consequently the machine may be found to operate quite smoothly and eiiiciently in striking olf and levelling the poured concrete. In the course of use the screeds 28 and 32 become worn in which event they can be readily removed and replaced.

From the above-described construction it will be appreciated that the improved machine is capable of performing adequately the rodding and screeding operations thathave heretofore been perforrneed by hand. Although the machine has the necessary weight to strike off a relatively large area of excess concrete, the' entire weight of the machine is not supported on the grounds or guide strips Ill and l l. Only sufficient weight is allowed to rest on these grounds to effectively strike off the concrete to the desired level. Thus, danger of disturbing kthe grounds is eliminated and the .concrete is levelled to the level determined by the temporarily mounted grounds.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. A portable concrete rodding machine comprising a transversely extending frame, means for moving the frame longitudinally, cross bars pivotally mounted upon the frame, transversely extending screeds pivo-tally connected to the cross bars, one of said screeds being disposed forwardly of the frame and the other rearwardly thereof, motor driven means on the frame for reciprocating the screeds, and means on the frame between the screeds engageable with the bed of concrete that is to be rodded to resist lateral movements of the machine.

2. A portable concrete redding machine comprising a transversely extending frame, means for moving the frame longitudinally, cross bars pivotally mounted upon the frame, transversely extending screeds pivotally connected to the cross bars, one of said screeds being disposed forwardly of the frame and the other rearwardly thereof whereby the weight-of the machine will tend to settle to that level limited by the engagement of the screeds with guide strips, and motor driven means on the frame for reciprocating one of the screeds causing the other to be simultaneously reciprocated but in the opposite direction.

3. A portable concrete rodding machine comprising a transversely extending frame, means for moving the frame longitudinally, cross barspivotally mounted upon the frame, transversely extending screeds pivotally connected to the bars', one of said screeds being disposed forwardly of the frame and the other rearwardly thereof whereby the weight uof the machine will tend to' settle to that level limited by the engagement of the screeds with guide strips, motor driven means' of the frame and the other rearwardly thereof V' whereby the weight of the machine will tend to settle to that level limited by the engagement of the screeds with guide strips, motor driven means on the frame for reciprocating one of the screeds causing the other to be simultaneously reciprocated but in the opposite direction, and wheels yieldably mounted upon the frame for assisting in supporting the frame for longitudinal movemerli?.

5. A portable concrete rodding machine comprising a transversely extending frame, means for moving the frame longitudinally, cross bars pivotally mounted upon the frame, transversely extending screeds pivotally connected to the cross bars, one of said screeds being disposed forwardly of the frame and the other rearwardly thereof whereby the weight of the machine will tend to settle to that level limited by the engagement of the screeds with guide strips, motor driven means on the frame for reciprocating one of the screeds causing thelother to be simultaneously reciprocated but in the opposite direction, and a wheel at each end of the frame the axis of rotation of which is in the same vertical plane as the pivots for the cross bars.

6. A portable concreterodding machine commoving the frame longitudinally, wheels adjacent j the ends of the frame arranged so that the frame l will be substantially balanced thereon, trans versely extending screeds at the front and backgpf the frame substantially equi-distant from the of rotation of the wheels, said Wheels constituting the sole means of support of the frame except for the supporting effect of 4the screeds, and motor driven means for reciprocating the screeds.

8. A portable concrete redding machine comprising a transversely extending frame, means for moving the frame longitudinally, wheels adjacent the ends of the frame engageable with the concrete bed to resist lateral movements of the machine and arranged so that the frame will De substantially balanced thereon, transversely extending screeds at the front and back of the frame substantially equi-distant from the axis of rotation of the wheels, said wheels constituting the sole support for the frame except for ,the supporting eiect of the screeds, and motor driven means for reciprocating the screeds simultaneously and in opposite directions.

9. A portable concrete redding machine comprising a transversely extending frame, a handle on the frame for moving the frame longitudinally,

wheels adjacent the ends of the frame arranged so that the frame will be substantially balanced thereon, said Wheels being engageable with the bed of concrete that is to be rodded to resist lateral movements of the machine, transversely extending screeds at the front and back of the frame substantially equi-distant from the axis of rotation of the wheels, and motor driven means for reciprocating the screeds, said wheels being yieldably mounted upon the frame so as to only partially carry the load of the frame enabling the balance of the Weight of the frame to press the screeds against guide strips.

10. A portable concrete rodding machine comprising a transversely extending frame, a handle on the frame for moving the frame longitudinally, wheels adjacent the ends of the frame arranged so that the frame will be substantially balanced thereon, transversely extending screeds at the front and back of the frame substantially equidistant from the axis of rotation of the wheels, levers pivotally mounted centrally upon the i frame and pivotally connected to the screeds, and

motor driven means on the frame for reciprocating one of the screeds causing. both screeds to be reciprocated simultaneously and in opposite directions.

11. A portable concrete rodding machine comprising a transversely extending frame, a handle on the frame for moving the frame longitudinally, transversely extending screeds at the front and back of the frame, motor driven means for reciprocating the screeds, and means for yieldably supporting the frame between the screeds whereby the frame and screeds may tend to be balanced about the supporting means and a portion of the Weight of the machine will be carried by the supporting means and the balance employed to press the screeds against guide strips.

MARVIN E. WHITEMAN. 

